1. Field of the Invention
This invention relates to automobile anti-theft devices, and more particularly concerns a locking device adapted to be mounted upon a hand brake lever handle of an automobile in a manner to prevent unauthorized use of the automobile.
2. Description of the Prior Art
A motor vehicle hand brake operating lever is generally designed to be manually moved between forward and rearward positions, thereby controlling an associated ratchet mechanism adapted to activate or release the vehicle's brakes. In the brake-activated position, the lever remains locked in position by virtue of the ratchet mechanism. A manually operable release member, such as a push-button, serves to lift a pawl from the ratchet mechanism, thereby permitting movement of the lever to the brake-released position. A motor vehicle having such a hand-brake is herein referred to as being "of the kind referred to", and such hand-brakes are sometimes referred to as "parking" or "emergency" brakes.
Numerous vehicular anti-theft devices have been disclosed in the prior art. Various locks have been employed in attempts to prevent theft of a motor vehicle, by preventing disengagement of a parking brake. For example, it has been proposed to replace the push-button ratchet release button on the extremity of a conventional hand-brake lever with a push-button having a cylinder lock incorporated therein. In such construction, the push-button can only be depressed when the lock is unlocked. However, such locking mechanisms have proved ineffective because the locking detent or the like employed by the lock can be fractured by a hammer blow applied to the push-button. One such locking device is disclosed in U.S. Pat. No. 5,134,784, wherein the lock is designed to resist fracturing. However, locks of this type have the inherent disadvantage that they must be factory installed within the hand brake lever. Therefore, retrofitting of an existing automobile with such a device would require replacement of the entire hand brake lever, and perhaps the associated ratchet assembly.
Locks have been proposed having a sleeve emplaced upon the lever of the hand-brake and having means for depressing the pushbutton of the hand-brake. In the locked condition of the lock, the depressing means cannot be moved. Such locking devices have been further provided with rotatable number dials wherein a predetermined combination of numbers opens the lock. A lock of this type is disclosed in U.S. Pat. No. 1,088,853.
The effectiveness of combination locks can be thwarted by individuals with sensitive feeling in the fingertips or sufficient aptitude and patience. In the case of multi-dial combination locks, the owner may inadvertently leave the lock with the opening combination showing, thereby enabling others to know said combination. The known locks are further burdened by the disadvantage that they do not comply with international safety standards. In accordance with such standards, release of the stopping brake of a motor vehicle during operation should not be impeded. In the case of known combination-based locks, it is possible that a number dial can be accidentally rotated out of the position corresponding to the unlocked condition of the locking device. In a dangerous situation, for example, when the service brake of the vehicle has become defective or failed, it is possible that the hand brake must be repeatedly applied and released. If in the meantime, at least one of the number dials has been shifted out of the unlocked condition, the once applied brake cannot be immediately released, thereby increasing the risk of an accident. A further disadvantage of such locks is the visual and manipulative difficulty which may be encountered in unlocking the device, particularly by vision-impaired individuals or in a substantially dark vehicle. In an emergency situation, such as a potential assault, robbery, or car-jacking, the critical time necessary to manipulate the lock to the unlocked position may seriously delay movement of the vehicle.
Other locking devices have been disclosed which seek to render a vehicle incapable of operation through the simultaneous locking of the hand-brake lever to either the gear shift lever or steering wheel. For example, U.S. Pat. No. 5,038,667 discloses a device which secures the hand brake lever to the gear shift lever of an automobile. This device is made up of two interactive limbs. One limb comprises a sleeve which is slid onto the hand brake lever, thereby preventing depression of the release button and attendant movement of the handle. The other limb has locking clamp means fastened around the gear shift lever. This device has many parts, is complicated, requiring two hands for emplacement and removal, and is not amenable to low cost manufacture.
U.S. Pat. No. 4,995,250 discloses a gear-shift-to-brake-lever lock device having a moveable sleeve and a main rod mounted with five combination rings. This lock has the aforesaid disadvantages of a combination lock and requires two hands to extend into locked position. Furthermore, it is expensive to manufacture and its use may put deleterious strain on the gear shift lever.
U.S. Pat. No. 4,825,671 discloses an extensible locking device having one extremity adapted to be locked around a steering wheel, and another extremity having a tube engaging the hand brake lever, thereby preventing depression of the release button. This device is expensive to produce and difficult to deploy and remove, requiring manipulation of two key locks, and two hands to operate.
It is accordingly an object of the present invention to provide a locking device for a hand-brake lever of a motor vehicle wherein depression of a release button on said lever may be prevented.
It is another object of the present invention to provide a locking device as in the foregoing object which may be easily installed upon hand-brake levers of existing vehicles.
It is a further object of this invention to provide a locking device of the aforesaid nature which is simple to deploy and remove, durable in construction and amenable to low cost manufacture.
These and other beneficial objects and advantages will be apparent from the following description.